Refractory and super-refractory status epilepticus in adults: a 9-year cohort study

Identification of etiologies according to baseline clinical features of pediatric new-onset refractory status epilepticus in single center retrospective study

PURPOSE

New-onset refractory status epilepticus (NORSE) is defined as a state of prolonged seizure activity that does not improve despite the appropriate administration of medications, with underlying causes unknown after the initial diagnosis of status epilepticus. Because episodes of NORSE are accompanied by severe complications and a high risk of mortality, the prompt identification of the underlying cause is crucial for effective treatment and outcome prediction. This study assessed the relationship of NORSE etiologies with baseline clinical features in pediatric population.

METHODS

Seventy-one pediatric patients, under 18 years of age at the initial diagnosis (4.50 ± 4.04, mean ± standard deviation), who experienced at least one episode of NORSE and underwent a comprehensive diagnostic evaluation between January 2005 and June 2020 at our center, were retrospectively selected. We reviewed clinical features at disease onset and long-term follow-up data. Uniform manifold approximation and projection (UMAP) was used to distinguish etiological clusters according to baseline clinical characteristics, and further analysis was performed based on underlying etiologies.

RESULTS

Two distinct etiological groups-genetic and non-genetic-were identified based on the UMAP of clinical characteristics. Dravet syndrome (12/15, 80%) was more predominant in patients with a genetic diagnosis, whereas cryptogenic NORSE and encephalitis were prevalent in patients without a genetic diagnosis. The analysis of etiological categories revealed that age at the onset of status epilepticus (P=0.021) and progression to super refractory status epilepticus (SRSE) (P=0.038) were independently associated with differences in etiologies.

CONCLUSION

Several clinical features in patients with NORSE, including the age of onset and the development of SRSE, can help identify underlying causes, which necessitate prompt and adequate treatment.

Emergent Management of Status Epilepticus

OBJECTIVE

Status epilepticus is a neurologic emergency that can be life- threatening. The key to effective management is recognition and prompt initiation of treatment. Management of status epilepticus requires a patient-specific-approach framework, consisting of four axes: (1) semiology, (2) etiology, (3) EEG correlate, and (4) age. This article provides a comprehensive overview of status epilepticus, highlighting the current treatment approaches and strategies for management and control.

LATEST DEVELOPMENTS

Administering appropriate doses of antiseizure medication in a timely manner is vital for halting seizure activity. Benzodiazepines are the first-line treatment, as demonstrated by three randomized controlled trials in the hospital and prehospital settings. Benzodiazepines can be administered through IV, intramuscular, rectal, or intranasal routes. If seizures persist, second-line treatments such as phenytoin and fosphenytoin, valproate, or levetiracetam are warranted. The recently published Established Status Epilepticus Treatment Trial found that all three of these drugs are similarly effective in achieving seizure cessation in approximately half of patients. For cases of refractory and super-refractory status epilepticus, IV anesthetics, including ketamine and γ-aminobutyric acid-mediated (GABA-ergic) medications, are necessary. There is an increasing body of evidence supporting the use of ketamine, not only in the early phases of stage 3 status epilepticus but also as a second-line treatment option.

ESSENTIAL POINTS

As with other neurologic emergencies, "time is brain" when treating status epilepticus. Antiseizure medication should be initiated quickly to achieve seizure cessation. There is a need to explore newer generations of antiseizure medications and nonpharmacologic modalities to treat status epilepticus.

Staged treatment response in status epilepticus: Lessons from the SENSE registry

OBJECTIVES

Although in epilepsy patients the likelihood of becoming seizure-free decreases substantially with each unsuccessful treatment, to our knowledge this has been poorly investigated in status epilepticus (SE). We aimed to evaluate the proportion of SE cessation and functional outcome after successive treatment steps.

METHODS

We conducted a post hoc analysis of a prospective, observational, multicenter cohort (Sustained Effort Network for treatment of Status Epilepticus [SENSE]), in which 1049 incident adult SE episodes were prospectively recorded at nine European centers. We analyzed 996 SE episodes without coma induction before the third treatment step. Rates of SE cessation, mortality (in ongoing SE or after SE control), and favorable functional outcome (assessed with modified Rankin scale) were evaluated after each step.

RESULTS

SE was treated successfully in 838 patients (84.1%), 147 (14.8%) had a fatal outcome (36% of them died while still in SE), and 11 patients were transferred to palliative care while still in SE. Patients were treated with a median of three treatment steps (range 1-13), with 540 (54.2%) receiving more than two steps (refractory SE [RSE]) and 95 (9.5%) more than five steps. SE was controlled after the first two steps in 45%, with an additional 21% treated after the third, and 14% after the fourth step. Likelihood of SE cessation (p < 0.001), survival (p = 0.003), and reaching good functional outcome (p < 0.001) decreased significantly between the first two treatment lines and the third, especially in patients not experiencing generalized convulsive SE, but remained relatively stable afterwards.

SIGNIFICANCE

The significant worsening of SE prognosis after the second step clinically supports the concept of RSE. However, and differing from findings in human epilepsy, RSE remains treatable in about one third of patients, even after several failed treatment steps. Clinical judgment remains essential to determine the aggressiveness and duration of SE treatment, and to avoid premature treatment cessation in patients with SE.

Neurosteroids as Novel Anticonvulsants for Refractory Status Epilepticus and Medical Countermeasures for Nerve Agents: A 15-Year Journey to Bring Ganaxolone from Bench to Clinic

This article describes recent advances in the use of neurosteroids as novel anticonvulsants for refractory status epilepticus (RSE) and as medical countermeasures (MCs) for organophosphates and chemical nerve agents (OPNAs). We highlight a comprehensive 15-year journey to bring the synthetic neurosteroid ganaxolone (GX) from bench to clinic. RSE, including when caused by nerve agents, is associated with devastating morbidity and permanent long-term neurologic dysfunction. Although recent approval of benzodiazepines such as intranasal midazolam and intranasal midazolam offers improved control of acute seizures, novel anticonvulsants are needed to suppress RSE and improve neurologic function outcomes. Currently, few anticonvulsant MCs exist for victims of OPNA exposure and RSE. Standard-of-care MCs for postexposure treatment include benzodiazepines, which do not effectively prevent or mitigate seizures resulting from nerve agent intoxication, leaving an urgent unmet medical need for new anticonvulsants for RSE. Recently, we pioneered neurosteroids as next-generation anticonvulsants that are superior to benzodiazepines for treatment of OPNA intoxication and RSE. Because GX and related neurosteroids that activate extrasynaptic GABA-A receptors rapidly control seizures and offer robust neuroprotection by reducing neuronal damage and neuroinflammation, they effectively improve neurologic outcomes after acute OPNA exposure and RSE. GX has been selected for advanced, Biomedical Advanced Research and Development Authority-supported phase 3 trials of RSE and nerve agent seizures. In addition, in mechanistic studies of neurosteroids at extrasynaptic receptors, we identified novel synthetic analogs with features that are superior to GX for current medical needs. Development of new MCs for RSE is complex, tedious, and uncertain due to scientific and regulatory challenges. Thus, further research will be critical to fill key gaps in evaluating RSE and anticonvulsants in vulnerable (pediatric and geriatric) populations and military persons. SIGNIFICANCE STATEMENT: Following organophosphate and nerve agent intoxication, refractory status epilepticus (RSE) occurs despite benzodiazepine treatment. RSE occurs in 40% of status epilepticus patients, with a 35% mortality rate and significant neurological morbidity in survivors. To treat RSE, neurosteroids are better anticonvulsants than benzodiazepines. Our pioneering use of neurosteroids for RSE and nerve agents led us to develop ganaxolone as a novel anticonvulsant and neuroprotectant with significantly improved neurological outcomes. This article describes the bench-to-bedside journey of bringing neurosteroid therapy to patients, with ganaxolone leading the way.

Status epilepticus in the ICU

Status epilepticus (SE) is a common medical emergency associated with significant morbidity and mortality. Management that follows published guidelines is best suited to improve outcomes, with the most severe cases frequently being managed in the intensive care unit (ICU). Diagnosis of convulsive SE can be made without electroencephalography (EEG), but EEG is required to reliably diagnose nonconvulsive SE. Rapidly narrowing down underlying causes for SE is crucial, as this may guide additional management steps. Causes may range from underlying epilepsy to acute brain injuries such as trauma, cardiac arrest, stroke, and infections. Initial management consists of rapid administration of benzodiazepines and one of the following non-sedating intravenous antiseizure medications (ASM): (fos-)phenytoin, levetiracetam, or valproate; other ASM are increasingly used, such as lacosamide or brivaracetam. SE that continues despite these medications is called refractory, and most commonly treated with continuous infusions of midazolam or propofol. Alternatives include further non-sedating ASM and non-pharmacologic approaches. SE that reemerges after weaning or continues despite management with propofol or midazolam is labeled super-refractory SE. At this step, management may include non-sedating or sedating compounds including ketamine and barbiturates. Continuous video EEG is necessary for the management of refractory and super-refractory SE, as these are almost always nonconvulsive. If possible, management of the underlying cause of seizures is crucial particularly for patients with autoimmune encephalitis. Short-term mortality ranges from 10 to 15% after SE and is primarily related to increasing age, underlying etiology, and medical comorbidities. Refractoriness of treatment is clearly related to outcome with mortality rising from 10% in responsive cases, to 25% in refractory, and nearly 40% in super-refractory SE.

How much refractory is 'refractory status epilepticus'? A retrospective study of treatment strategies and clinical outcomes

BACKGROUND AND PURPOSE

This study aimed to evaluate whether differences in clinical outcomes exist according to treatments received and seizure activity resolution in patients with refractory status epilepticus (RSE).

METHODS

Consecutive episodes of non-hypoxic status epilepticus (SE) in patients ≥ 14 years old were included. Episodes of RSE were stratified in: (i) SE persistent despite treatment with first-line therapy with benzodiazepines and one second-line treatment with antiseizure medications (ASMs), but responsive to successive treatments with ASMs (RSE-rASMs); (ii) SE persistent despite treatment with first-line therapy with benzodiazepines and successive treatment with one or more second-line ASMs, but responsive to anesthetic drugs [RSE-rGA (general anesthesia)]. Study endpoints were mortality during hospitalization and worsening of modified Rankin Scale (mRS) at discharge.

RESULTS

Status epilepticus was responsive in 298 (54.1%), RSE-rASMs in 152 (27.6%), RSE-rGA in 46 (8.3%), and super-refractory (SRSE) in 55 (10.0%) out of 551 included cases. Death during hospitalization occurred in 98 (17.8%) and worsening of mRS at discharge in 287 (52.1%) cases. Multivariable analyses revealed increased odds of in-hospital mortality with RSE-rGA (odds ratio [OR] 3.05, 95% confidence interval [CI] 1.27-7.35) and SRSE (OR 3.83, 95%. CI 1.73-8.47), and increased odds of worsening of mRS with RSE-rASMs (OR 2.06, 95% CI 1.28-3.31), RSE-rGA (OR 4.44, 95% CI 1.97-10.00), and SRSE (OR 13.81, 95% CI 5.34-35.67).

CONCLUSIONS

In RSE, varying degrees of refractoriness may be defined and suit better the continuum spectrum of disease severity and the heterogeneity of SE burden and prognosis.

Cardiac Abnormalities in Refractory Status Epilepticus-an Exploratory Study

Background and Purpose

Cardiac abnormalities have been reported during ongoing seizures and refractory status epilepticus (RSE). Reduced heart rate variability (HRV) and cardiac arrhythmias may contribute to sudden unexpected death in epilepsy. We sought to explore the utility of electrocardiographic and echocardiographic changes in patients with RSE prognosis and functional outcome.

Methods

Patients of RSE underwent electrocardiogram (ECG), holter, troponin-I (Trop I), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and 2-dimensional echocardiogram (2D Echo) along with continuous electroencephalogram in first 24 hours and admission. Heart rate changes/arrhythmias, corrected QT interval (QTc) and HRV, ventricular dysfunction or regional motion wall abnormality were studied on 2D Echo. These parameters were also at baseline, at discharge or death and 30 days post discharge.

Results

This prospective observational study conducted over 18 months enrolled 20 patients with RSE, fulfilling the inclusion criteria. Mean age was 47.75±17.2 years with male: female ratio of 1:1. Mean time to presentation from seizure onset was 8.80±7.024 hours. Central nervous system infection (35.0%), autoimmune encephalitis (20.0%) and cerebrovascular disease (20.0%) were the common etiologies. Amongst cardiac injury markers, cardiac enzymes and QTc prolongation were the commonest abnormalities in RSE. Both reduced HRV and presence of cardiac injury markers had significant correlation with poor outcome along with poor Glasgow coma scale (GCS) and modified Rankin scale (mRS) at presentation, and presence of non convulsive status epilepticus (NCSE).

Conclusions

Presence of poor GCS, poor mRS, markers of cardiac injury, reduced HRV and occurrence of NCSE have a consistent correlation with mortality and poor clinical outcome. Therefore, routine assessment of cardiac abnormalities using affordable, easily accessible and non-invasive tools such as ECG, 2D Echo, holter NT-proBNP and Trop I is recommended in RSE patients.

Further advances in epilepsy

In 2017, one of us reviewed advances in epilepsy (Manford in J Neurol 264:1811-1824, 2017). The current paper brings that review up to date and gives a slight change in emphasis. Once again, the story is of evolution rather than revolution. In recognition that most of our current medications act on neurotransmitters or ion channels, and not on the underlying changes in connectivity and pathways, they have been renamed as antiseizure (ASM) medications rather than antiepileptic drugs. Cenobamate is the one newly licensed medication for broader use in focal epilepsy but there have been a number of developments for specific disorders. We review new players and look forward to new developments in the light of evolving underlying science. We look at teratogenicity; old villains and new concerns in which clinicians play a vital role in explaining and balancing the risks. Medical treatment of status epilepticus, long without evidence, has benefitted from high-quality trials to inform practice; like buses, several arriving at once. Surgical treatment continues to be refined with improvements in the pre-surgical evaluation of patients, especially with new imaging techniques. Alternatives including stereotactic radiotherapy have received further focus and targets for palliative stimulation techniques have grown in number. Individuals' autonomy and quality of life continue to be the subject of research with refinement of what clinicians can do to help persons with epilepsy (PWE) achieve control. This includes seizure management but extends to broader considerations of human empowerment, needs and desires, which may be aided by emerging technologies such as seizure detection devices. The role of specialist nurses in improving that quality has been reinforced by specific endorsement from the International League against Epilepsy (ILAE).

Outcomes and Treatment Approaches for Super-Refractory Status Epilepticus: A Systematic Review and Meta-Analysis

Importance

Super-refractory status epilepticus (SRSE) is defined as status epilepticus (SE) that continues or recurs 24 hours or more after the onset of anesthetic therapy or recurs on the reduction/withdrawal of anesthesia. Current clinical knowledge of the disease and optimal treatment approach is sparse.

Objective

To systematically assess clinical characteristics, causes, outcomes, prognostic factors, and treatment approaches for patients with SRSE.

Design, Setting, and Participants

In this systematic review and meta-analysis, all studies reporting adult patients (18 years or older) diagnosed with nonanoxic SRSE were considered for inclusion, irrespective of study design. The databases used were MEDLINE, Cochrane Library, EMBASE, and ClinicalTrials.org (database inception through May 5, 2022).

Data extraction and synthesis

The study complied with the PRISMA guidelines for reporting, data extraction, and data synthesis. Different tools were used to assess risk of bias. All available data were extracted and missing data were neither imputed nor completed by contacting the study authors.

Main outcome and measures

Successful treatment of SRSE, in-hospital mortality, and disability at discharge (estimated modified Rankin Scale).

Results

The study team identified a total of 95 articles and 30 conference abstracts reporting 1200 patients with nonanoxic SRSE (266 individual patients were available for meta-analysis). They had a mean SRSE duration of 36.3 days, mean age of 40.8 years, and equal sex distribution. Patients with SRSE had a distinct pattern of etiologies where acute cerebral events and unknown etiologies accounted for 41.6% and 22.3% of all etiologies, respectively. Reports of SRSE caused by, eg, alcohol, drugs, or tumors were rare. At discharge, only 26.8% had none to slight disability (none, 16 [8.4%]; nonsignificant and slight disability, 35 [18.4%]). In-hospital mortality was 24.1%. Mortality stabilized after long-term treatment (more than 28 days) but with increased rates of seizure cessation and moderate to severe disability. Established prognostic factors, such as age and etiology, were not associated with in-hospital mortality. Reported treatment with ketamine, phenobarbital, other barbiturates, vagus nerve stimulator, and ketogenic diet were not associated with outcome.

Conclusion and Relevance

Patients with SRSE are distinct due to their pattern of care (eg, long-term treatment to younger patients without negative prognostic factors and unknown/nonmalignant etiologies) and their natural course of SE. Very long-term treatment was associated with lower mortality and high odds of cessation of SRSE but increased risk of moderate to severe disability.

A practical approach to in-hospital management of new-onset refractory status epilepticus/febrile infection related epilepsy syndrome

New-onset refractory status epilepticus (NORSE) is "a clinical presentation, not a specific diagnosis, in a patient without active epilepsy or other preexisting relevant neurological disorder, with new onset of refractory status epilepticus without a clear acute or active structural, toxic, or metabolic cause." Febrile infection related epilepsy syndrome (FIRES) is "a subcategory of NORSE that requires a prior febrile infection, with fever starting between 2 weeks and 24 h before the onset of refractory status epilepticus, with or without fever at the onset of status epilepticus." These apply to all ages. Extensive testing of blood and CSF for infectious, rheumatologic, and metabolic conditions, neuroimaging, EEG, autoimmune/paraneoplastic antibody evaluations, malignancy screen, genetic testing, and CSF metagenomics may reveal the etiology in some patients, while a significant proportion of patients' disease remains unexplained, known as NORSE of unknown etiology or cryptogenic NORSE. Seizures are refractory and usually super-refractory (i.e., persist despite 24 h of anesthesia), requiring a prolonged intensive care unit stay, often (but not always) with fair to poor outcomes. Management of seizures in the initial 24-48 h should be like any case of refractory status epilepticus. However, based on the published consensus recommendations, the first-line immunotherapy should begin within 72 h using steroids, intravenous immunoglobulins, or plasmapheresis. If there is no improvement, the ketogenic diet and second-line immunotherapy should start within seven days. Rituximab is recommended as the second-line treatment if there is a strong suggestion or proof of an antibody-mediated disease, while anakinra or tocilizumab are recommended for cryptogenic cases. Intensive motor and cognitive rehab are usually necessary after a prolonged hospital stay. Many patients will have pharmacoresistant epilepsy at discharge, and some may need continued immunologic treatments and an epilepsy surgery evaluation. Extensive research is in progress now via multinational consortia relating to the specific type(s) of inflammation involved, whether age and prior febrile illness affect this, and whether measuring and following serum and/or CSF cytokines can help determine the best treatment.

The Roles of Glutamate Receptors and Their Antagonists in Status Epilepticus, Refractory Status Epilepticus, and Super-Refractory Status Epilepticus

Status epilepticus (SE) is a neurological emergency with a high mortality rate. When compared to chronic epilepsy, it is distinguished by the durability of seizures and frequent resistance to benzodiazepine (BZD). The Receptor Trafficking Hypothesis, which suggests that the downregulation of γ-Aminobutyric acid type A (GABAA) receptors, and upregulation of N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors play major roles in the establishment of SE is the most widely accepted hypothesis underlying BZD resistance. NMDA and AMPA are ionotropic glutamate receptor families that have important excitatory roles in the central nervous system (CNS). They are both essential in maintaining the normal function of the brain and are involved in a variety of neuropsychiatric diseases, including epilepsy. Based on animal and human studies, antagonists of NMDA and AMPA receptors have a significant impact in ending SE; albeit most of them are not yet approved to be in clinically therapeutic guidelines, due to their psychomimetic adverse effects. Although there is still a dearth of randomized, prospective research, NMDA antagonists such as ketamine, magnesium sulfate, and the AMPA antagonist, perampanel, are regarded to be reasonable optional adjuvant therapies in controlling SE, refractory SE (RSE) or super-refractory SE (SRSE), though there are still a lack of randomized, prospective studies. This review seeks to summarize and update knowledge on the SE development hypothesis, as well as clinical trials using NMDA and AMPA antagonists in animal and human studies of SE investigations.

Thyroid storm in a pregnant woman with COVID-19 infection: A case report and review of literatures

BACKGROUND

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been found to be responsible for the recent global pandemic known as coronavirus disease 2019 (COVID-19). SARS-CoV-2 infections not only result in significant respiratory symptoms but also cause several extrapulmonary manifestations, such as thrombotic complications, myocardial dysfunction and arrhythmia, thyroid dysfunction, acute kidney injury, gastrointestinal symptoms, neurological symptoms, ocular symptoms, and dermatological complications. We present the first documented case of thyroid storm in a pregnant woman precipitated by SARS-CoV-2.

CASE SUMMARY

A 42-year-old multiparous woman at 35 + 2 wk of gestation visited the emergency room (ER) with altered mentation, seizures, tachycardia, and high fever. The patient showed no remarkable events in the prenatal examination, and the nasopharyngeal COVID-19 polymerase chain reaction (PCR) test was positive two days before the ER visit. The results of laboratory tests, such as liver function test, serum electrolytes, blood glucose, blood urea nitrogen, and creatinine, were all within the normal ranges. However, the thyroid function test showed hyperthyroidism, and the nasopharyngeal COVID-19 PCR test was positive, as expected. No specific findings were observed on the brain computed tomography, and there were no signs of lateralization on neurological examination. Fetal heartbeat and movement were good, and there were no significant uterine contractions. The initial impression was atypical eclampsia. However, the patient's condition worsened, and a cesarean section was performed under general anesthesia; a healthy boy was delivered, and 12 h after delivery, the patient's seizures disappeared and consciousness was restored. The patient was referred to an endocrinologist for hyperthyroidism, and a thyroid storm with Graves' disease was diagnosed. Here, SARS-CoV-2 was believed to be the trigger for the thyroid storm, considering that the patient tested positive for COVID-19 two days before the seizures.

CONCLUSION

In pregnant women presenting with seizures or changes in consciousness, the possibility of a thyroid storm should be considered. There are various causes for a thyroid storm, but given the recent pandemic, it is necessary to bear in mind that the thyroid storm may be precipitated by COVID-19.

Specific profiles of new-onset vs. non-inaugural status epilepticus: From diagnosis to 1-year outcome

While new-onset status epilepticus (NOSE) is a harbinger of chronic epilepsy, prospective medical data are sparse in terms of specifying whether the evolution of status epilepticus (SE) and seizure expression in NOSE resembles what occurs in patients who have already been diagnosed with epilepsy [non-inaugural SE (NISE)] in all aspects apart from its inaugural nature. The aim of this study was to compare the clinical, MRI, and EEG features that could distinguish NOSE from NISE. We conducted a prospective monocentric study in which all patients ≥18 years admitted for SE over a 6-month period were included. A total of 109 patients (63 NISE and 46 NOSE cases) were included. Despite similar modified Rankin scores before SE, several aspects of the clinical history distinguished NOSE from NISE patients. NOSE patients were older and frequently had neurological comorbidity and preexisting cognitive decline, but they had a similar prevalence of alcohol consumption to NISE patients. NOSE and NISE evolve in the same proportions as refractory SE (62.5% NOSE, 61% NISE) and share common features such as the same incidence (33% NOSE, 42% NISE, and p = 0.53) and volumes of peri-ictal abnormalities on MRI. However, in NOSE patients, we observed greater non-convulsive semiology (21.7% NOSE, 6% NISE, and p = 0.02), more periodic lateral discharges on EEG (p = 0.004), later diagnosis, and higher severity according to the STESS and EMSE scales (p < 0.0001). Mortality occurred in 32.6% of NOSE patients and 21% of NISE patients at 1 year (p = 0.19), but with different causes of death occurring at different time points: more early deaths directly linked to SE at 1 month occurred in the NOSE group, while there were more remote deaths linked to causal brain lesions in the NISE group at final follow-up. In survivors, 43.6% of the NOSE cases developed into epilepsy. Despite acute causal brain lesions, the novelty related to its inaugural nature is still too often associated with a delay in diagnosing SE and a poorer outcome, which justifies the need to more clearly specify the various types of SE to constantly raise awareness among clinicians. These results highlight the relevance of including novelty-related criteria, clinical history, and temporality of occurrence in the nosology of SE.

[Status epilepticus-Detection and treatment in the intensive care unit]

Status epilepticus is characterized by persistent or repetitive seizures which, without successful treatment, can lead to neuronal damage, neurological deficits and death of the patient.While status epilepticus with motor symptoms can usually be clinically diagnosed, nonconvulsive status epilepticus is often clinically overlooked due to its ambiguous semiology, so that electroencephalography (EEG) recording is necessary. The treatment of status epilepticus is performed in four treatment steps, whereby a difficult to treat status epilepticus is present from the third step at the latest and intensive medical care of the patient is necessary. Timely initiation of treatment and sufficient dosage of anticonvulsive medication are decisive for the success of treatment. There is little evidence for the "late" stages of treatment. Intensive medical measures pose the risk of complications that worsen the prognosis. Especially in nonconvulsive status epilepticus, the use of anesthetics must be weighed against possible complications of mechanical ventilation.

Predicting the progression to super-refractory status epilepticus: A machine-learning study

AIM

Super-refractory status epilepticus (SRSE) is a status epilepticus (SE) that continues or recurs ≥24 h after the onset of anesthesia. We aimed to identify the predictors of progression to SRSE and the risk of 30-day mortality in patients with SRSE by using a machine learning technique.

METHODS

We reviewed consecutive SE episodes in patients aged ≥14 years at Baggiovara Civil Hospital (Modena, Italy) from 2013 to 2021. A classification and regression tree analysis was performed to develop a predictive model of progression to SRSE in SE patients. In SRSE patients, a multivariate analysis was conducted to identify predictors of 30-day mortality.

RESULTS

We included 705 patients, 16% of whom (113/705) progressed to SRSE. Acute symptomatic hypoxic etiology and age ≤ 68.5 years predicted the highest risk (87.1%) of progression to SRSE. Etiology other than acute symptomatic hypoxic and absence of NCSE predicted the lowest risk (3.6%) of progression to SRSE. The predictive model was accurate in 96.1% of patients not evolving to SRSE and in 48.7% of those evolving to SRSE. Among patients with SRSE, 46.9% (53/113) died within 30 days compared to 25.2% (149/592) of patients without SRSE (p < 0.001). Among patients with SRSE, older age was associated with increased 30-day mortality (odds ratio 1.075; 95% confidence interval: 1.031-1.112; p = 0.001).

CONCLUSIONS

Acute symptomatic hypoxic etiology and younger age are major predictors of progression to SRSE. In patients with SRSE, older age is associated with increased risk of short-term mortality.

Management of Refractory Status Epilepticus: An International Cohort Study (MORSE CODe) Analysis of Patients Managed in the ICU

BACKGROUND AND OBJECTIVES

Status epilepticus that continues after the initial benzodiazepine and a second anticonvulsant medication is known as refractory status epilepticus (RSE). Management is highly variable because adequately powered clinical trials are missing. We aimed to determine whether propofol and midazolam were equally effective in controlling RSE in the intensive care unit, focusing on management in resource-limited settings.

METHODS

Patients with RSE treated with midazolam or propofol between January 2015 and December 2018 were retrospectively identified among 9 centers across 4 continents from upper-middle-income economies in Latin America and high-income economies in North America, Europe, and Asia. Demographics, Status Epilepticus Severity Score, etiology, treatment details, and discharge modified Rankin Scale (mRS) were collected. The primary outcome measure was good functional outcome defined as a mRS score of 0-2 at hospital discharge.

RESULTS

Three hundred eighty-seven episodes of RSE (386 patients) were included, with 162 (42%) from upper-middle-income and 225 (58%) from high-income economies. Three hundred six (79%) had acute and 79 (21%) remote etiologies. Initial RSE management included midazolam in 266 (69%) and propofol in 121 episodes (31%). Seventy episodes (26%) that were initially treated with midazolam and 42 (35%) with propofol required the addition of a second anesthetic to treat RSE. Baseline characteristics and outcomes of patients treated with midazolam or propofol were similar. Breakthrough (odds ratio [OR] 1.6, 95% CI 1.3-2.0) and withdrawal seizures (OR 2.0, 95% CI 1.7-2.5) were associated with an increased number of days requiring continuous intravenous anticonvulsant medications (cIV-ACMs). Prolonged EEG monitoring was associated with fewer days of cIV-ACMs (1-24 hours OR 0.5, 95% CI 0.2-0.9, and >24 hours OR 0.7, 95% CI 0.5-1.0; reference EEG <1 hour). This association was seen in both, high-income and upper-middle-income economies, but was particularly prominent in high-income countries. One hundred ten patients (28%) were dead, and 80 (21%) had good functional outcomes at hospital discharge.

DISCUSSION

Outcomes of patients with RSE managed in the intensive care unit with propofol or midazolam infusions are comparable. Prolonged EEG monitoring may allow physicians to decrease the duration of anesthetic infusions safely, but this will depend on the implementation of RSE management protocols. Goal-directed management approaches including EEG targets may hold promise for patients with RSE.

CLASSIFICATION OF EVIDENCE

This study provides Class III data that propofol and midazolam are equivalently efficacious for RSE.

Factors associated with mortality in patients with super-refractory status epilepticus

Super-refractory status epilepticus (SRSE) is a critical condition in which seizures persist despite anesthetic use for 24 h or longer. High mortality has been reported in patients with SRSE, but the cause of death remains unclear. We investigated the factors associated with mortality, including clinical characteristics, SE etiologies and severities, treatments, and responses in patients with SRSE in a 13-year tertiary hospital-based retrospective cohort study comparing these parameters between deceased and surviving patients. SRSE accounted for 14.2% of patients with status epilepticus, and 28.6% of SRSE patients died. Deceased patients were mostly young or middle-aged without known systemic diseases or epilepsy. All deceased patients experienced generalized convulsive status epilepticus and failure of anesthetic tapering-off, significantly higher than survivors. An increased number of second-line anesthetics besides midazolam was observed in the deceased (median, 3, interquartile range 2–3) compared to surviving (1, 1–1; p = 0.0006) patients with prolonged use durations (p = 0.047). For mortality, the cut-off number of second-line anesthetics was 1.5 (AUC = 0.906, p = 0.004). Deceased patients had significantly higher renal and cardiac complications and metabolic acidosis than survivors. In SRSE management, multi-anesthetic use should be carefully controlled to avoid systemic complications and mortality.

Ketamine in adult super-refractory status epilepticus: Efficacy analysis on a prospective registry

Background

Status epilepticus (SE) persisting despite two anti‐seizures medications (ASM) and anesthetics is labeled super refractory (SRSE), correlating with important morbidity and mortality. Its treatment relies on expert opinions. Due to its pharmacological properties, ketamine (KET) has received increasing attention, but data are essentially retrospective.

Aims

To describe an unselected cohort of adults receiving KET for SRSE.

Methods

Analysis of a prospective registry of consecutive SE episodes, identifying SRSE patients receiving ketamine (KET). Comparison with recent adult series including more than 10 patients.

Results

Eleven patients received KET after a median of 4 days (range: 2–20); median dose was 5 mg/kg/h (range: 2.5–15). KET provided permanent SE control in three (27%). Previous series, using KET administration delays and doses similar to our cohort, report KET efficacy in 28–96% of cases.

Conclusions

We found a lower SE control rate than existing literature, whose data are, however, often retrospective, potentially selecting patients with less severe SE forms or responding to KET. This might explain outcome differences, as KET administration modalities were comparable with our cohort. Since randomized controlled studies are lacking on this subject, the analysis of this prospective, unselected cohort, if confirmed, suggests a current overestimation of KET efficacy in SRSE.

Specific characteristics and current diagnostic and treatment modalities performance of super refractory status epilepticus in children: A comparative study

OBJECTIVE

Super-refractory status epilepticus (SRSE) is associated with significant morbidity and mortality in children. We explored the clinical spectrum, specific characteristics, and outcome in SRSE patients admitted in a pediatric intensive care unit (PICU) and investigated how well current diagnostic or treatment modalities perform compared to Status Epilepticus (SE) and Refractory SE (RSE) patients.

METHODS

Retrospective analysis of PICU patients admitted with convulsive SE during 2009-2019. Eighty-six patients were classified as SE, RSE, and SRSE. New-onset RSE (NORSE) and febrile infection-related epilepsy syndrome (FIRES) were also identified. Functional outcome was evaluated by the modified Rankin scale.

RESULTS

Patients with SRSE (n = 20) had longer weaning off anesthetics (p = 0.014), length of stay, mechanical ventilation duration, higher illness severity scores, and poorer outcome compared to SE (n = 13) or RSE (n = 53) patients (all p < 0.001). Diagnosis, mainly expressed by high prevalence of NORSE (n = 13) and FIRES (n = 9), was independently associated with SRSE (p = 0.024). Abnormal MRI findings (p = 0.005), and epilepsy-related pathogenic variants identified by whole-exome sequencing (WES) were mostly found in SRSE patients. Compared to intravenous immunoglobulins and steroid pulses, plasmapheresis and ketogenic diet, more often used in SRSE (p < 0.01), contributed better to seizure control. Only SRSE (AUROC > 0.80, 95% CI = 0.68-0.94, p < 0.001) and diagnosis (AUROC > 0.70, 95% CI = 0.55-0.83, p = 0.02) could predict a poor outcome.

CONCLUSION

The majority of SRSE patients are characterized by considerable functional decline and morbidity. WES analysis may reveal epilepsy-related pathogenic variants while early aggressive immunotherapy and/or ketogenic diet might prove beneficial. Multicenter studies for prediction models of outcome are needed.

Management of status epilepticus: a narrative review

Status epilepticus causes prolonged or repetitive seizures that, if left untreated, can lead to neuronal injury, severe disability, coma and death in paediatric and adult populations. While convulsive status epilepticus can be diagnosed using clinical features alone, non-convulsive status epilepticus requires confirmation by electroencephalogram. Early seizure control remains key in preventing the complications of status epilepticus. This is especially true for convulsive status epilepticus, which has stronger evidence supporting the benefit of treatment on outcomes. When status epilepticus becomes refractory, often due to gamma-aminobutyric acid and N-methyl-D-aspartate receptor modulation, anaesthetic drugs are needed to suppress seizure activity, of which there is limited evidence regarding the selection, dose or duration of their use. Seizure monitoring with electroencephalogram is often needed when patients do not return to baseline or during anaesthetic wean; however, it is resource-intensive, costly, only available in highly specialised centres and has not been shown to improve functional outcomes. Thus, the treatment goals and aggressiveness of therapy remain under debate, especially for non-convulsive status epilepticus, where prolonged therapeutic coma can lead to severe complications. This review presents an evidence-based, clinically-oriented and comprehensive review of status epilepticus and its definitions, aetiologies, treatments, outcomes and prognosis at different stages of the patient's journey.

Super-Refractory Status Epilepticus in Children: A Retrospective Cohort Study

OBJECTIVES

To characterize the pediatric super-refractory status epilepticus population by describing treatment variability in super-refractory status epilepticus patients and comparing relevant clinical characteristics, including outcomes, between super-refractory status epilepticus, and nonsuper-refractory status epilepticus patients.

DESIGN

Retrospective cohort study with prospectively collected data between June 2011 and January 2019.

SETTING

Seventeen academic hospitals in the United States.

PATIENTS

We included patients 1 month to 21 years old presenting with convulsive refractory status epilepticus. We defined super-refractory status epilepticus as continuous or intermittent seizures lasting greater than or equal to 24 hours following initiation of continuous infusion and divided the cohort into super-refractory status epilepticus and nonsuper-refractory status epilepticus groups.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified 281 patients (157 males) with a median age of 4.1 years (1.3-9.5 yr), including 31 super-refractory status epilepticus patients. Compared with nonsuper-refractory status epilepticus group, super-refractory status epilepticus patients had delayed initiation of first nonbenzodiazepine-antiseizure medication (149 min [55-491.5 min] vs 62 min [33.3-120.8 min]; p = 0.030) and of continuous infusion (495 min [177.5-1,255 min] vs 150 min [90-318.5 min]; p = 0.003); prolonged seizure duration (120 hr [58-368 hr] vs 3 hr [1.4-5.9 hr]; p < 0.001) and length of ICU stay (17 d [9.5-40 d] vs [1.8-8.8 d]; p < 0.001); more medical complications (18/31 [58.1%] vs 55/250 [22.2%] patients; p < 0.001); lower return to baseline function (7/31 [22.6%] vs 182/250 [73.4%] patients; p < 0.001); and higher mortality (4/31 [12.9%] vs 5/250 [2%]; p = 0.010). Within the super-refractory status epilepticus group, status epilepticus resolution was attained with a single continuous infusion in 15 of 31 patients (48.4%), two in 10 of 31 (32.3%), and three or more in six of 31 (19.4%). Most super-refractory status epilepticus patients (30/31, 96.8%) received midazolam as first choice. About 17 of 31 patients (54.8%) received additional treatments.

CONCLUSIONS

Super-refractory status epilepticus patients had delayed initiation of nonbenzodiazepine antiseizure medication treatment, higher number of medical complications and mortality, and lower return to neurologic baseline than nonsuper-refractory status epilepticus patients, although these associations were not adjusted for potential confounders. Treatment approaches following the first continuous infusion were heterogeneous, reflecting limited information to guide clinical decision-making in super-refractory status epilepticus.

Can occurrence of convulsive status epilepticus during video telemetry be predicted? Observations from an epilepsy monitoring unit

PURPOSE

The objective of the study was to evaluate the frequency, clinical, and video-electroencephalographic (VEEG) predictors of convlusive status epilepticus (CSE) in the epilepsy-monitoring unit (EMU).

METHODS

The data of all patients who had CSE in our EMU between 2008 and 2017 were reviewed. For each case, two age- and diagnosis-matched subjects who underwent VEEG and did not develop CSE were taken as internal controls. Electro-clinical data of both the groups were compared. Predictors of CSE were assessed using logistic regression analysis.

RESULTS

Out of 11,188 video-telemetries were conducted between 2008-17, forty-three events of CSE (0.38%) were recorded. On comparisons with 86 internal controls no differences were apparent on prevalence of cognitive impairment, structural lesion, number of baseline anti-seizure medications (ASM), ASM taper schedule, ictal patterns, and duration of VEEG monitoring. Inter-ictal rhythmic periodic patterns had significantly higher prevalence in cases (p = 0.028). Logistic regression analysis revealed that odds of CSE were higher with past history of SE [p = 0.008; adjusted odds ratio (OR) = 5.48 (confidence intervals {CI} 1.55-19.28)] and in presence of rhythmic spike and wave discharges [p = 0.016, OR = 33.518(CI = 1.93-581.4)]; the odds were lower if the first two seizures recorded did not evolve into CSE [p = 0.009, OR = 0.247 (CI = 0.08-0.70)] and if there was prior history of daily seizures [p = 0.02, OR = 0.250 (CI = 0.07-0.84)].

CONCLUSION

CSE is a rare yet important adverse event in EMU. Clinical predictors are more relevant in comparison to EEG variables. Extent of ASM withdrawal may not directly account for occurrence of CSE; factors inherent to a patient's epilepsy are deterministic.

An Insight into the Current Understanding of Status Epilepticus: From Concept to Management

Status epilepticus (SE), a subset of epilepsy, represents a debilitating neurological disorder often associated with alarming mortality and morbidity numbers. Even though SE is one of the extensively researched topics with conspicuous data available in the literature, a scientific gap exists in understanding the heterogeneous facets of the disorder like occurrence, definition, classification, causes, molecular mechanisms, etc., thereby providing a defined management program. Cognizance of this heterogeneity and scientific limitation with its subsequent correlation to the recent advancements in medical and scientific domains would serve not only in bridging the gap but also in developing holistic and prompt management programs. Keeping this as an objective, an extensive literature survey was performed during this study, and key findings have been shared. The present study provides a semantic and perspective synopsis toward acknowledging the diversified nature of SE and its variants with respect to their definition, classification, etiology, diagnosis, and management.

Review and Updates on the Treatment of Refractory and Super Refractory Status Epilepticus

Refractory and super-refractory status epilepticus (RSE and SRSE) are life-threatening conditions requiring prompt initiation of appropriate treatment to avoid permanent neurological damage and reduce morbidity and mortality. RSE is defined as status epilepticus that persists despite administering at least two appropriately dosed parenteral medications, including a benzodiazepine. SRSE is status epilepticus that persists at least 24 h after adding at least one appropriately dosed continuous anesthetic (i.e., midazolam, propofol, pentobarbital, and ketamine). Other therapeutic interventions include immunotherapy, neuromodulation, ketogenic diet, or even surgical intervention in certain cases. Continuous electroencephalogram is an essential monitoring tool for diagnosis and treatment. In this review, we focus on the diagnosis and treatment of RSE and SRSE.

Understanding new-onset refractory status epilepticus from an immunological point of view

New-onset refractory status epilepticus (NORSE) is unexpected onset of refractory status epilepticus in individuals with no preexisting relevant neurologic condition. The etiologies remain largely cryptogenic; treatment is challenging after failure to control seizures despite use of multiple antiepileptic drugs and anesthetic agents. Frequent fever and other infectious prodromes, elevated proinflammatory cytokine/chemokine levels, and limbic or multifocal brain lesions indicate active inflammation in NORSE. Among identified causes, autoimmune encephalitis is the most common and accounts for more than one-third of all known NORSE cases, followed by infection-related etiologies. Although more evidence is needed, anti-cytokine therapies with tocilizumab and anakinra along with other immunotherapeutic agents used in autoimmune encephalitis can aid in alleviating or hindering the inflammatory cascade and controlling seizures.

Evaluation and Management of Seizures and Status Epilepticus

Seizures are frequently triggered by an inciting event and result from uninhibited excitation and/or decreased inhibition of a pool of neurons. If physiologic seizure abortive mechanisms fail, the ensuing unrestrained synchronization of neurons-status epilepticus-can be life-threatening and is associated with the potential for marked morbidity in survivors and high medical care costs. Prognosis is intimately related to etiology and its response to therapeutic measures. Timely implementation of pharmacologic therapy while concurrently performing a stepwise workup for etiology are paramount. Neurodiagnostic testing should guide titration of pharmacologic therapies, and help determine if there is a role for immune modulation.

Fenfluramine in the successful treatment of super-refractory status epilepticus in a patient with Dravet syndrome

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Dravet syndrome (DS) patient in super-refractory status epilepticus (SRSE) for 5 weeks.

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Add-on fenfluramine (FFA) successfully treated SRSE in DS.

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Most effective dose of FFA was 0.7 mg/kg/day.

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Long-term FFA provided >90% reduction in seizures and prevented status epilepticus.

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FFA maintenance also resulted in improvement of neurocognitive function.

A 20-year-old woman with Dravet syndrome and multiple prior episodes of status epilepticus presented to our hospital in November 2018 in super-refractory status epilepticus. After 5 weeks of unsuccessful continuous treatment with anesthetics, including pentobarbital and ketamine, we sought and were granted an emergency approval by the United States Food and Drug Administration to administer fenfluramine, an investigational new drug, to this patient. One week of treatment with fenfluramine at 0.4 mg/kg/day was ineffective. The dose of fenfluramine was titrated to 0.7 mg/kg/day, and after 1 week, electrographic seizures ceased. One week later, the patient was seizure-free and off all anesthetic agents. Add-on treatment with fenfluramine was continued with no further episodes of status epilepticus and >90% reduction in tonic-clonic seizures. This case report illustrates the potential for fenfluramine to prevent reoccurrence of status epilepticus and to manage super-refractory status epilepticus in patients with Dravet syndrome.

Status epilepticus with prominent motor symptoms clusters into distinct electroclinical phenotypes

BACKGROUND AND PURPOSE

Status epilepticus (SE) is a heterogeneous condition and considerable variability exists in its etiology, semiology, electroencephalographic correlates, and response to treatment. The aim of the present study was to explore whether distinct phenotypes may be identified within SE with prominent motor symptoms.

METHODS

Consecutive episodes of SE with prominent motor symptoms in patients aged ≥14 years were included. Etiology of SE was defined as symptomatic (acute, remote, progressive) or unknown. Electroencephalogram (EEG) recordings were searched for lateralized periodic discharges (LPDs), generalized sharply and/or triphasic periodic potentials (GPDs), and spontaneous burst suppression (BS). According to treatment response, SE was classified into responsive, refractory and super-refractory. Average linkage hierarchical cluster analysis was performed with Pearson's correlation as a similarity measure.

RESULTS

A total of 240 episodes of SE were identified. Three major clusters were found. The first cluster linked focal motor SE evolving into non-convulsive SE (NCSE), presence of LPDs/GPDs on EEG, unknown etiology and treatment refractoriness. The second cluster linked convulsive and myoclonic SE evolving into NCSE, presence of spontaneous BS on EEG, progressive symptomatic etiology and super-refractoriness. The third cluster linked convulsive and myoclonic SE not evolving into other semiologies, absence of LPDs/GPDs/spontaneous BS on EEG, acute symptomatic etiology and treatment responsiveness.

CONCLUSIONS

Distinct electroclinical phenotypes characterized by different response to pharmacological intervention can be identified within the heterogeneity of SE with prominent motor phenomena.

Predictors of outcome in super refractory status epilepticus

PURPOSE

We conducted this study to determine the clinical, electrophysiological and radiological predictors of outcome in Super Refractory Status Epilepticus (SRSE).

METHODS

Data of patients treated for SRSE between January 2000 and November 2019, archived prospectively in our SE registry were analyzed. Functional outcome was measured by Glasgow outcome score (GOS) at the time of hospital discharge and was divided into: good i.e. GOS ≥ 3 and bad outcome i.e. GOS < 3. The predictors of outcome were determined using appropriate statistical tests by univariate and multivariate analysis, p < 0.05 was considered as statistically significant.

RESULTS

Of the 384 patients with status epilepticus (SE) identified during the study, 28 (8%) were diagnosed as SRSE and were included in the final analysis. Acute symptomatic SE comprising 15 (53.6%) patients was the most common etiology of SRSE. Thirteen patients (three patients with viral encephalitis and 10 patients with clinically possible autoimmune encephalitis) had New Onset Refractory Status Epilepticus (NORSE) like clinical presentation.12 patients (42.9%) had good outcome and 16 patients (57.1%) had bad outcome. Multivariate logistic regression analysis showed that independent predictors of poor outcome were: duration of ICU stay (p < 0.001); EEG findings such as non-convulsive SE in coma (0.032), spontaneous burst suppression (0.001) and postictal diffuse attenuation (<0.001); delay in starting anesthesia (0.002); and delay in starting immunotherapy in NORSE due to autoimmune encephalitis (0.002).

CONCLUSION

We could determine independent therapeutic and electrophysiological prognostic factors for SRSE. Early initiation of treatment and stringent management of these factors especially in an younger age-group, aided by continuous EEG monitoring and a thorough etiological work-up can result in good outcomes in more than one-third of cases.

Not all patients with convulsive status epilepticus intubated in pre-hospital settings meet the criteria for refractory status epilepticus

INTRODUCTION

Mechanically ventilated patients admitted to the intensive care unit (ICU) for generalized convulsive status epilepticus (GCSE) are a heterogeneous population. Our objective was to evaluate the number of patients who fulfilled the diagnostic criteria for refractory GCSE and describe their initial management and prognosis.

METHODS

This multicenter retrospective study was conducted in four French ICUs in Pitié-Salpêtrière University Hospital in Paris and in the Hospital of Jossigny. Mechanically ventilated patients admitted to the ICU for GCSE between, January 1, 2014, and, December 31, 2016, were included. Patients with anoxia and traumatic brain injury were excluded. Their pre-hospital and ICU medical records were reviewed. The collected data included pre-hospital clinical status, pre-hospital antiepileptic treatment, reason for mechanical ventilation, duration of general anesthesia, and prognosis in the ICU. A retrospective initial diagnosis based on the findings of the analysis of the clinical records was attributed to each patient.

RESULTS

Among the 98 patients included, 88.8% (n = 87/98) fulfilled the diagnostic criteria for GCSE; of these cases, 16.1% (n = 14/87) were refractory. Eleven percent of the patients did not fulfill the criteria for GCSE at the time of initial management (retrospective diagnosis of single convulsive seizure, repetitive convulsive seizures, or psychogenic non-epileptic seizures). Most patients were intubated for coma (58.9%, n = 56/95, missing data: n = 3). In the ICU, the median [Q1-Q3] duration of general anesthesia before weaning was 12.3 h (5.0-18.0 h); 7% of the patients had a relapse of status epilepticus, and 2% died in the ICU.

CONCLUSION

Among the cases of confirmed GCSE in the mechanically ventilated patients admitted to the ICU, 16.1% were refractory, with an overall good prognosis. A significant proportion of patients did not fulfill the diagnostic criteria for refractory GCSE.

The Need to Intervene Before Time Point 2: Evidence From Clinical and Animal Data That Status Epilepticus Damages the Brain

Status epilepticus, a condition characterized by abnormally prolonged seizures, has the potential to cause irreversible, structural or functional, injury to the brain. Unfavorable consequences of these seizures include mortality, the risk of developing epilepsy, and cognitive impairment. We highlight key findings of clinical and laboratory studies that have provided insights into aspects of cell death, and anatomical and functional alterations triggered by status epilepticus that support the need to intervene before time point 2, the time after which the risk of these long-term consequences increases.

Status Epilepticus: Definition, Classification, Pathophysiology, and Epidemiology

Status epilepticus (SE) is the state of continuous or repetitive seizures, which can occur with or without convulsions. Evolving definitions of SE take into account the concept that neuronal injury may occur at different times in different types of SE.SE that does not respond to initial treatment may become refractory or even super-refractory. Nonconvulsive SE is increasingly recognized in comatose patients in critical care units, with the growing use of continuous electroencephalogram monitoring. SE is a neurologic emergency that carries a high risk of mortality and morbidity.

First-line medication dosing in pediatric refractory status epilepticus

OBJECTIVE

To identify factors associated with low benzodiazepine (BZD) dosing in patients with refractory status epilepticus (RSE) and to assess the impact of BZD treatment variability on seizure cessation.

METHODS

This was a retrospective study with prospectively collected data of children with convulsive RSE admitted between June 2011 and January 2019. We analyzed the initial and total BZD dose within 10 minutes of treatment initiation. We used logistic regression modeling to evaluate predictors of low BZD dosing and multivariate Cox regression analysis to assess the impact of low BZD dosing on time to seizure cessation.

RESULTS

We included 289 patients (55.7% male) with a median age of 4.3 (1.3-9.5) years. BZDs were the initial medication in 278 (96.2%). Of those, 161 patients (57.9%) received a low initial dose. Low initial BZD doses occurred in both out-of-hospital (57 of 106; 53.8%) and in-hospital (104 of 172; 60.5%) settings. One hundred three patients (37.1%) received low total BZD dose. Male sex (odds ratio [OR] 2, 95% confidence interval [CI] 1.18-3.49; p = 0.012), older age (OR 1.1, 95% CI 1.05-1.17; p < 0.001), no prior diagnosis of epilepsy (OR 2.1, 95% CI 1.23-3.69; p = 0.008), and delayed BZD treatment (OR 2.2, 95% CI 1.24-3.94; p = 0.007) were associated with low total BZD dose. Patients who received low total BZD dosing were less likely to achieve seizure cessation (hazard ratio 0.7, 95% CI 0.57-0.95).

CONCLUSION

BZD doses were lower than recommended in both out-of-hospital and in-hospital settings. Factors associated with low total BZD dose included male sex, older age, no prior epilepsy diagnosis, and delayed BZD treatment. Low total BZD dosing was associated with decreased likelihood of Seizure cessation.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that patients with RSE who present with male sex, older age, no prior diagnosis of epilepsy, and delayed BZD treatment are more likely to receive low total BZD doses. This study provides Class III evidence that in pediatric RSE low total BZD dose decreases the likelihood of seizure cessation.

Drug Trials in Status Epilepticus: Current Evidence and Future Concepts

Status epilepticus (SE) is a neurologic emergency with high morbidity and mortality. After many advances in the field, several unanswered questions remain for optimal treatment after the early stage of SE. This narrative review describes some of the important drug trials for SE treatment that have shaped the understanding of the treatment of SE. The authors also propose possible clinical trial designs for the later stages of SE that may allow assessment of currently available and new treatment options. Status epilepticus can be divided into four stages for treatment purposes: early, established, refractory, and superrefractory. Ongoing convulsive seizures for more than 5 minutes or nonconvulsive seizure activity for more than 10 to 30 minutes is considered early SE. Failure to control the seizure with first-line treatment (usually benzodiazepines) is defined as established SE. If SE continues despite treatment with an antiseizure medicine, it is considered refractory SE, which is usually treated with additional antiseizure medicines or intravenous anesthetic agents. Continued seizures for more than 24 hours despite use of intravenous anesthetic agents is termed superrefractory SE. Evidence-based treatment recommendations from high-quality clinical trials are available for only the early stages of SE. Among the challenges for designing a treatment trial for the later stages SE is the heterogeneity of semiology, etiology, age groups, and EEG correlates. In many instances, SE is nonconvulsive in later stages and diagnosis is possible only with EEG. EEG patterns can be challenging to interpret and only recently have consensus criteria for EEG diagnosis of SE emerged. Despite having these EEG criteria, interrater agreement in EEG interpretation can be challenging. Defining successful treatment can also be difficult. Finally, the ethics of randomizing treatment and possibly using a placebo in critically ill patients must also be considered. Despite these challenges, clinical trials can be designed that navigate these issues and provide useful answers for how best to treat SE at various stages.

Therapeutic Options for Patients with Refractory Status Epilepticus in Palliative Settings or with a Limitation of Life-Sustaining Therapies: A Systematic Review

BACKGROUND

Refractory status epilepticus (RSE) represents a serious medical condition requiring early and targeted therapy. Given the increasing number of elderly or multimorbid patients with a limitation of life-sustaining therapy (LOT) or within a palliative care setting (PCS), guidelines-oriented therapy escalation options for RSE have to be omitted frequently.

OBJECTIVES

This systematic review sought to summarize the evidence for fourth-line antiseizure drugs (ASDs) and other minimally or non-invasive therapeutic options beyond guideline recommendations in patients with RSE to elaborate on possible treatment options for patients undergoing LOT or in a PCS.

METHODS

A systematic review of the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, focusing on fourth-line ASDs or other minimally or non-invasive therapeutic options was performed in February and June 2020 using the MEDLINE, EMBASE and Cochrane databases. The search terminology was constructed using the name of the specific ASD or therapy option and the term 'status epilepticus' with the use of Boolean operators, e.g. "(brivaracetam) AND (status epilepticus)". The respective Medical Subject Headings (MeSH) and Emtree terms were used, if available.

RESULTS

There is currently no level 1, grade A evidence for the use of ASDs in RSE. The best evidence was found for the use of lacosamide and topiramate (level 3, grade C), followed by brivaracetam, perampanel (each level 4, grade D) and stiripentol, oxcarbazepine and zonisamide (each level 5, grade D). Regarding non-medicinal options, there is little evidence for the use of the ketogenic diet (level 4, grade D) and magnesium sulfate (level 5, grade D) in RSE. The broad use of immunomodulatory or immunosuppressive treatment options in the absence of a presumed autoimmune etiology cannot be recommended; however, if an autoimmune etiology is assumed, steroid pulse, intravenous immunoglobulins and plasma exchange/plasmapheresis should be considered (level 4, grade D). Even if several studies suggested that the use of neurosteroids (level 5, grade D) is beneficial in RSE, the current data situation indicates that there is formal evidence against it.

CONCLUSIONS

RSE in patients undergoing LOT or in a PCS represents a challenge for modern clinicians and epileptologists. The evidence for the use of ASDs in RSE beyond that in current guidelines is low, but several effective and well-tolerated options are available that should be considered in this patient population. More so than in any other population, advance care planning, advance directives, and medical ethical aspects have to be considered carefully before and during therapy.

Application of ketogenic diets for pediatric neurocritical care

In this review, we summarize the general mechanisms of the ketogenic diet, and the application of a ketogenic diet in pediatric intensive care units for the neurological disorders of children and young infants. A ketogenic diet is a high-fat, low-carbohydrate, adequate-protein diet. It can alter the primary cerebral energy metabolism from glucose to ketone bodies, which involves multiple mechanisms of antiepileptic action, antiepileptogenic properties, neuro-protection, antioxidant and anti-inflammatory effects, and it is potentially a disease-modifying intervention. Although a ketogenic diet is typically used for the chronic stage of pharmacoresistant of epilepsy, recent studies have shown its efficacy in patients with the acute stage of refractory/super-refractory status epilepticus. The application of a ketogenic diet in pediatric intensive care units is a challenge because of the critical status of the patients, who are often in a coma or have a nothing by mouth order. Moreover, a ketogenic diet needs to be started early and sometimes through parenteral administration in patients with critical conditions such as refractory status epilepticus or febrile infection-related epilepsy syndrome. Animal models and some case reports have shown that the neuro-protective effects of a ketogenic diet can be extended to other emergent neurological diseases, such as traumatic brain injury and ischemic stroke.

Factors affecting mortality of refractory status epilepticus

OBJECTIVE

The aim of this study was to determine the factors affecting the mortality of refractory status epilepticus (RSE) in comparison with non-refractory status epilepticus (non-RSE).

MATERIAL-METHOD

Included in this retrospective study were 109 status epilepticus cases who were hospitalized in the neurological intensive care unit Katip Celebi University. Fifty-two were RSE and 57 were non-RSE. All clinical data were gathered from the hospital archives. Factors which may cause mortality were categorized for statistical analysis.

RESULTS

While elderly age, continuous clinical seizure activity, absence of former seizure, infection, prolonged stay of ICU, anesthesia, and cardiac comorbidity were significantly related to mortality in the RSE subgroup, potentially fatal accompanying diseases were significantly related to mortality in the non-RSE subgroup. No significant relationship was found between mortality and refractoriness. Multivariate analysis revealed that a Glasgow Coma Score (GCS) at presentation of 8 or lower was the independent predictor of mortality both in the general SE population (P = .017) and in the RSE subgroup (P = .007). Intubation (P = .011) and hypotension (P = .011) were the other independent predictors of mortality in the general SE population. No independent predictor of mortality was detected in the non-RSE subgroup.

DISCUSSION/CONCLUSION

Intubation, hypotension, and a low GCS at presentation could be the main factors which could alert clinicians of an increased risk of mortality in SE patients. Although non-RSE and RSE had similar rates of mortality in the ICU, the mortality-related factors of SE vary in the RSE and the non-RSE subgroups.

Hypothermia as a treatment in status epilepticus: A narrative review

Status epilepticus (SE) is associated with high mortality and morbidity rates, notably in its refractory and super-refractory forms. This narrative review discusses recent data on the potential benefits of targeted temperature management. In studies of patients with cerebral injury due to various factors, therapeutic hypothermia had variable effects on survival and functional outcomes. Sources of this variability may include the underlying etiology, whether hypothermia was used for prophylaxis or treatment, the degree and duration of hypothermia, and the hypothermia application modalities. Data from animal studies strongly suggest benefits from therapeutic hypothermia in SE. In humans, beneficial effects have been described in anecdotal case reports and small case series, but the level of evidence is low. A randomized controlled trial found no evidence that moderate hypothermia (32-34 °C) was neuroprotective in critically ill patients with convulsive SE. Nevertheless, some promising effects were noted, suggesting that therapeutic hypothermia might have a role as an adjuvant to anticonvulsant drug therapy in patients with refractory or super-refractory SE. This article is part of a Special Issue entitled "Status Epilepticus". This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".

[Management of refractory and super-refractory status epilepticus]

If status epilepticus continues despite the use of intravenous antiepileptic drugs or narcotics, it is called "refractory" or "super-refractory" status epilepticus (RSE, SRSE). Prolonged seizure activity is associated with neuronal damage, systemic complications and mortality rates of up to 50%, especially in generalized tonic clonic seizure types. In order to terminate the status, several rescue interventions with drugs and other measures are available. However, their evidence base is low because the effectiveness of the measures was almost exclusively derived from case reports and case series. In individual cases, a good outcome is possible even after several months of ongoing SRSE.

Change in Mortality of Generalized Convulsive Status Epilepticus in High-Income Countries Over Time: A Systematic Review and Meta-analysis

Importance

Status epilepticus (SE) is associated with significant morbidity and mortality. Since the late 1990s, a more aggressive management of prolonged convulsive seizures lasting longer than 5 minutes has been advocated.

Objective

To determine if convulsive SE mortality has decreased during a time of increasing advocacy for out-of-hospital treatment and escalating and earlier treatment protocols for prolonged seizures and SE.

Data Source

This systemic review and meta-analysis on studies focused on the mortality of convulsive status epilepticus was conducted by searching MEDLINE, Embase, PsychINFO, CINAHL Plus, and the Cochrane Database of Systematic Reviews between January 1, 1990, and June 30, 2017.

Study Selection

Studies were excluded if they had fewer than 30 participants (<20 for refractory SE), were limited to SE of single specific etiology or an evaluation of a single treatment modality, or were studies of nonconvulsive SE.

Data Extraction and Synthesis

Data were abstracted and their quality was assessed via a modified Newcastle-Ottawa scale independently by 2 reviewers (A.N. and T.D.G.) using the Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines. Data were pooled using a random-effects model.

Main Outcomes and Measures

The main outcome measure was in-hospital mortality or 30-day case fatality expressed as proportional mortality.

Results

Sixty-one studies were included in the analysis. The pooled mortality ratios were 15.9% (95% CI, 12.7-19.2) for adult studies, 13.0% (95% CI, 7.2-19.0) for all-age population studies, 3.6% (95% CI, 2.0%-5.2%) for pediatric studies, and 17.3% (95% CI, 9.8-24.7) for refractory SE studies, with very high between-study heterogeneity. We found no evidence of a change in prognosis over time nor by the definition of SE used.

Conclusions and Relevance

The mortality of convulsive SE is higher in adults than in children and there was no evidence for improved survival over time. Although there are many explanations for these findings, they can be explained by aetiology of SE being the major determinant of mortality. However, there are potential confounders, including differences in case ascertainment and study heterogeneity. This meta-analysis highlights the need for strict international guidelines for the study of this condition.

Use of intravenous brivaracetam in status epilepticus: A multicenter registry

OBJECTIVE

The pharmacokinetics of brivaracetam (BRV), added to its effectiveness observed in animal models of status epilepticus (SE), makes this drug attractive for use in emergency situations. Our objective was to evaluate the use of intravenous BRV in a multicenter study.

METHODS

A retrospective multicenter registry of SE cases treated with BRV was created. These patients were evaluated between January and December 2018 at seven hospitals in Spain. Demographic variables, SE characteristics, concomitant drugs, loading doses, and response to treatment were collected.

RESULTS

Forty-three patients were registered. The mean age was 56 ± 23.1 years, 51.2% were male, 29 had previous epilepsy, 24 (55.8%) had prominent motor symptoms, and 19 had nonconvulsive symptoms. Regarding the etiology, 19 (44.2%) were considered acute symptomatic, 16 (17.2%) remote symptomatic, four (9.3%) progressive symptomatic, and four (9.3%) cryptogenic. Regarding concomitant antiepileptic drugs (AEDs), 17 had previously received levetiracetam (LEV). In 14 patients, BRV was used early (first or second AED). The median loading dose was 100 mg (range = 50-400), and the weight-adjusted dose was 1.8 mg/kg (range = 0.4-7.3). BRV was effective in 54% (n = 23), and a response was observed in <6 hours in 13 patients. We observed a tendency for it to be more effective when administered earlier (P = 0.09), but there were no differences regarding SE type and the concomitant use of LEV. In those with the fastest responses, we observed that both the total administered dose (300 mg vs 100 mg, P = 0.008) and the weight-adjusted dose (3.85 mg vs 1.43 mg, P = 0.006) were significantly higher. The receiver operating characteristic curve showed that the best cutoff point for a faster response was 1.82 mg/kg.

SIGNIFICANCE

BRV is useful for the treatment of SE, even when patients are already being treated with LEV. The response rate seems higher when it is administered earlier and at higher doses (>1.82 mg/kg).

Status epilepticus in Auckland, New Zealand: Incidence, etiology, and outcomes

OBJECTIVE

To determine the incidence, etiology, and outcome of status epilepticus (SE) in Auckland, New Zealand, using the latest International League Against Epilepsy (ILAE) SE semiological classification.

METHODS

We prospectively identified patients presenting to the public or major private hospitals in Auckland (population = 1.61 million) between April 6, 2015 and April 5, 2016 with a seizure lasting 10 minutes or longer, with retrospective review to confirm completeness of data capture. Information was recorded in the EpiNet database.

RESULTS

A total of 477 episodes of SE occurred in 367 patients. Fifty-one percent of patients were aged <15 years. SE with prominent motor symptoms comprised 81% of episodes (387/477). Eighty-four episodes (18%) were nonconvulsive SE. Four hundred fifty episodes occurred in 345 patients who were resident in Auckland. The age-adjusted incidence of 10-minute SE episodes and patients was 29.25 (95% confidence interval [CI] = 27.34-31.27) and 22.22 (95% CI = 20.57-23.99)/100 000/year, respectively. SE lasted 30 minutes or longer in 250 (56%) episodes; age-adjusted incidence was 15.95 (95% CI = 14.56-17.45) SE episodes/100 000/year and 12.92 (95% CI = 11.67-14.27) patients/100 000/year. Age-adjusted incidence (10-minute SE) was 25.54 (95% CI = 23.06-28.24) patients/100 000/year for males and 19.07 (95% CI = 16.91-21.46) patients/100 000/year for females. The age-adjusted incidence of 10-minute SE was higher in Māori (29.31 [95% CI = 23.52-37.14]/100 000/year) and Pacific Islanders (26.55 [95% CI = 22.05-31.99]/100 000/year) than in patients of European (19.13 [95% CI = 17.09-21.37]/100 000/year) or Asian/other descent (17.76 [95% CI = 14.73-21.38]/100 000/year). Seventeen of 367 patients in the study died within 30 days of the episode of SE; 30-day mortality was 4.6%.

SIGNIFICANCE

In this population-based study, incidence and mortality of SE in Auckland lie in the lower range when compared to North America and Europe. For pragmatic reasons, we only included convulsive SE if episodes lasted 10 minutes or longer, although the 2015 ILAE SE classification was otherwise practical and easy to use.

Good Outcome in Cardiac Arrest Patients in Refractory Status Epilepticus: A Result of Aggressive Treatment or EEG Reclassification

[Box: see text]

The ketogenic diet for super-refractory status epilepticus patients in intensive care units

OBJECTIVES

Super-refractory status epilepticus (SRSE) is one of the most challenging issues in intensive care units (ICUs) in that it is associated with high morbidity and mortality. Although the ketogenic diet (KD) has been reported to be effective in treating of SRSE, the use of the diet as therapy can be complicated by concomitant medical problems specific to critically ill patients. In this study, we aimed to describe our experience of the KD for SRSE patients in ICUs.

METHODS

We retrospectively reviewed the medical records of 16 patients (10 males, 6 females) with SRSE who were treated with the KD in the ICUs at Samsung Medical Center from July 2005 to July 2017.

RESULTS

The median age of seizure onset was 8 years (interquartile range 5-13.5). Prior to diet initiation, the patients were in convulsive or non-convulsive SRSE for a median of 23 days (range, 3-420). The median time to achieve ketosis was 3 days (range, 2-6). The KD was continued for a median of 2.1 months (range, 0.1-15.8). Of the 16 patients, nine (56.3%) achieved seizure freedom, six (37.5%) reported >50% seizure reduction, and one (6.2%) had <50% seizure improvement after the KD. There was no significant change in the number of antiepileptic drugs. The most commonly encountered complication during the KD was gastrointestinal disturbance.

CONCLUSIONS

Our experience indicates that the KD is an effective alternative therapeutic strategy for SRSE patients in ICUs with adequate efficacy and safety in reducing seizure frequency and weaning from prolonged mechanical ventilation, although functional outcome was not favorable for most patients. Close monitoring and preventive management of potential adverse effects are critical elements for success with the KD in patients with SRSE.

The Outcome of Status Epilepticus and Long-Term Follow-Up

Objective: This study was to investigate the outcome of status epilepticus (SE) associated with antiepileptic therapy during SE and in follow-up period, risk factors including age, co-morbidities, pre-existing epilepsy, and etiology in the East-Hungarian region.

Methods: A prospective cross-sectional database was compiled from outpatient files between 2013 and 2017. Follow-up ended on 30.06.2018.

Results: One hundred and thirty five episodes (male: 68, 50.4%) were evaluated, mean age and follow-up time being 64.1 ± 13.9 years and 39.9 ± 14.2 months, respectively. Of the 89 patients with pre-existing epilepsy, 34 failed to visit the outpatient unit regularly. Case fatality rate was 25.2% and 31 patients (30.7%) died after discharge due to co-morbidities; their mean survival time was 10.44 ± 8 months. Focal, generalized and combined type epilepsies were diagnosed in 67 patients (49.6%), 47 patients (34.8%), and 21 patients (15.6%) of SE, respectively. Nine patients had non-convulsive SE (NCSE). Mean seizure-free period was 6.8 ± 6.9 months. Patients taking carbamazepine (20.9%; OR: 0.37, 95%CI: 0.16–0.82; p = 0.018), levetiracetam (27.5%; OR: 0.51, 95%CI: 0.27–0.97; p = 0.041), or valproate (11.1%; OR: 0.18, 95%CI: 0.05–0.61; p = 0.0043) were expected to achieve seizure freedom after SE. The worst outcome was linked to advanced age, etiology, new onset status epilepticus, NCSE, and focal status epilepsy.

Conclusion: This study highlights the importance of regular care and patient follow-up.

New onset refractory status epilepticus research: What is on the horizon?

New-onset refractory status epilepticus (NORSE) is a clinical presentation, not a specific diagnosis, in a patient without active epilepsy or other preexisting relevant neurologic disorder, with new onset of refractory status epilepticus (RSE) that does not resolve after 2 or more rescue medications, without a clear acute or active structural, toxic, or metabolic cause. Febrile infection-related epilepsy syndrome is a subset of NORSE in which fever began at least 24 hours prior to the RSE. Both terms apply to all age groups. Until recently, NORSE was a poorly recognized entity without a consistent definition or approach to care. We review the current state of knowledge in NORSE and propose a roadmap for future collaborative research. Research investigating NORSE should prioritize the following 4 domains: (1) clinical features, etiology, and pathophysiology; (2) treatment; (3) adult and pediatric evaluation and management approaches; and (4) public advocacy, professional education, and family support. We consider international collaboration and multicenter research crucial in achieving these goals.

Intravenous Corticosteroids as an Adjunctive Treatment for Refractory and Super-Refractory Status Epilepticus: An Observational Cohort Study

INTRODUCTION

Status epilepticus (SE) represents a neurological emergency that leads to considerable morbidity and mortality. Following failure of first-line therapy, usually with benzodiazepines, there is no clear evidence to guide treatment of refractory SE, although a wide variety of approaches has been described anecdotally.

OBJECTIVE

The aim of this study was to assess the clinical response to corticosteroids in adults with refractory and super-refractory SE, describing, to the best of our knowledge, the first adult SE cohort treated with corticosteroids.

METHODS

We retrospectively analysed our adult SE registry (2006-2017), identifying 15 out of 987 episodes (1.5%) in which corticosteroids were prescribed de novo as adjuvant therapy to a variety of antiepileptic drug regimens. We analysed incident episodes and defined clinical response as SE ceasing within 1 week of administration, without any other medical intervention.

RESULTS

Out of 987 SE episodes, 15 (1.5%) were treated with de novo corticosteroids, corresponding to 12 patients, with increasing prevalence as the SE became refractory (10/411; 2.4% of episodes) and super-refractory (5/108; 4.6% of episodes). One patient (a woman with Rasmussen encephalitis) presented with four SE episodes over a period of 3 years, so only her index SE episode was included in subsequent analyses. The episodes treated were predominantly of inflammatory origin (6/12), such as autoimmune or Rasmussen encephalitis. In five out of 12 (42%) of the considered incident episodes, SE resolved following corticosteroids (all within 3 days). The outcome was better in this responders group (for 2/5 episodes, patients did not have a new handicap at discharge, versus 0/7 in non-responders). In patients with inflammatory and acute symptomatic causes, global prognosis was better than in those with progressive or neurodegenerative aetiologies (6/8 vs. 4/4 had a new handicap at discharge or died).

CONCLUSIONS

Our observations seem to support the use of corticosteroids, especially for acute SE of putative inflammatory origin; these compounds, however, were prescribed infrequently.